不同种类微生物及其碳酸酐酶对土壤-灰岩系统钙镁锌元素迁移作用的土柱模拟实验研究

通过土柱模拟实验研究了筛选自西南岩溶区的典型细菌、真菌、放线菌对石灰岩的溶蚀动态及作用效果,并研究了这3种类群微生物及其碳酸酐酶(CA)对土壤-灰岩系统Ca、Mg、Zn元素迁移的影响。结果表明:①实验所用的典型细菌、真菌、放线菌均对石灰岩有较强的溶蚀作用,但是不同类群的微生物对石灰岩的溶蚀效果不同,溶蚀后石灰岩的表面形貌变化不同,其中,真菌的溶蚀效果最显著,放线菌和细菌次之;②典型细菌、真菌、放线菌对不同元素迁移的影响不同,对于Zn2 、Ca2 的迁移影响而言,真菌>放线菌>细菌>无菌对照组;对于Mg2 的迁移影响而言,细菌>真菌>放线菌>无菌对照组;③一定范围内温度增加对Ca、Mg、Zn3种元素的迁移有不同程度的促进作用;④土柱淋出液中CA平均活性与Ca、Mg、Zn3种元素的总淋失量之间存在一定的正相关关系,说明CA对这3种元素的迁移具有一定的影响,且因不同元素而异。本研究结果对于评价不同类群微生物在生物岩溶及岩溶系统元素迁移中的作用和地位提供了一定的科学依据。

Effect of Different Kinds of Microbes and Their Carbonic Anhydrase on Element Migration of Ca, Mg and Zn in Soil-Limestone Systems: Stimulated Column Experiments

The dynamics and effects of corrosion induced by the typical bacteria,fungi and actinomycetes separated from soils in Karst areas of Southwest China were studied by simulated soil column experiments,and the relationship between microbial carbonic anhydrase (CA) activities and element migration of Ca,Mg and Zn in soil-limestone systems were investigated. The results showed that: 1) Typical bacteria,fungi and actinomycetes used in the experiments had strong influences on limestone corrosion,but there were differences in corrosive effects of limestone among different kinds of microbes,and the surface shape of limestone varied with different kinds of microbes. Among the three kinds of microbes in the simulated soil column experiments,fungi had the most significant corrosive effect,and the next were actinomycetes,while the last were bacteria; 2) The effects of the three kinds of typical microbes on migration of different elements were different. The amount of migration of Zn2 and Ca2 were fungi>actinomycetes>bacteria>CK,and the amount of migration of Mg2 was bacteria>Fungi>Actinomycetes>CK; 3) Temperature could improve soil microbial effects on element migration of Ca,Mg and Zn; 4) There was a positive correlation between the mean activity of carbonic anhydrase (CA) and the total amount of Ca2 ,Mg2 and Zn2 in leachates of soil columns,which indicated that CA had a certain influence on the migration of these three kinds of elements,and the influence varied with different elements. These above results may provide scientific basis to evaluate the roles and status of different kinds of microbes in biokarst and element migration in Karst systems.